Benefits of Electrocoagulation for Hotel Grey Water Reuse
Published on by Nick Nicholas, App Eng/Technical Director at Genesis Water Technologies, Inc. in Technology
One of the most effective ways to reduce water consumption in hospitality is to treat and reuse grey water or wastewater.
Gray water reuse is not only beneficial to the operating costs of hotels, but it is also a more efficient and sustainable way to use water.
What is Grey water?
The wastewater resulting from the activities mentioned above is known as grey water. It differs from other domestic wastewater because it is typically cleaner, as it does not contain fecal matter from toilets. This fact makes grey water easier to treat than domestic sewage, with fewer solids and pathogens. In addition, with few contaminants to treat, grey water is a great source for reusable water, requiring less energy to treat and reuse. This gray water can be reused for land irrigation, laundry, toilet water, cooling towers, or cleaning water. Basically most non-potable applications.
How can this Grey water be treated?
One avenue for the treatment of grey water for reuse is to utilize electrocoagulation (EC) as part of a grey water treatment system. EC has been used in many industrial applications to great effect, and so it can certainly be effective for grey water treatment & reuse.
It works by supplying current to an array of metal electrodes (typically iron or aluminum or both). From within the solution, the anode oxidizes and releases ions into the effluent that neutralize the overall charge of the solution. At a neutral charge, particles will no longer repel one another and will coagulate. On the other side, the cathode reduces the water and causes hydrogen gas bubbles to form and rise to the surface, carrying these coagulated particles, like oils and solids to the surface where they form a floc layer.
So how does this work for grey water contaminants?
This research presentation from an institute in India has some great information on how EC works and its removal efficiencies for COD, BOD, turbidity, and coliforms. Grey water can contain hardness, silica, and sulfate, and while it does not have the same levels as toilet water, gray water does contain some level of pathogens (measured in fecal coliform and total coliform concentrations). Hardness, silica, and sulfate are all precipitated out of suspension as solids during the destabilization and end up as sludge separated in a post-EC clarification process. As for any bacteria, the electricity and oxidation actually weakens cell membranes and kills them.
Studies have shown EC to eliminate up to 100% of E. coli bacteria and coliform bacteria in wastewater samples.
Therefore, aside from the obvious benefit of water reuse and the removal of the contaminants, EC treatment of gray water has several additional noted benefits. Read all about them in the article attached below.
To learn more about Electrocoagulation, contact Genesis Water Technologies or read this article: Electrocoagulation Provides an Economical Produced Water Solution to Oil & Gas Companies
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- Electrocoagulation
- Decentralized Wastewater
- Water Reuse & Recycling
- Water Reclamation
- Water Resources
- Water Recycling
- Reuse
- Sustainability
- Environmental Engineers & Consultants